The present invention is related to hypodermic syringes and ampules, and mechanisms for causing needles thereof to penetrate the flesh for delivery of medicaments therefrom into the flesh. While the invention is useful to physicians, paramedics, nurses or the like, and to patients who are required to self-administer medicaments such as insulin in cases of diabetes.
Injector devices for facilitating hypodermic injections are known, both for medicament ampules that are furnished with the injector device, and for conventional hypodermic syringes that are operated by the device. In the case of injection from self-contained ampules, see, for example, U.S. Pat. Nos. 4,194,505, 4,316,463, and 4,413,991 to the present inventor, and U.S. Pat. No. 3,712,301 to Sarnoff. For injection from conventional syringes, see U.S. Pat. Nos. 4,494,358 to Fehlis, 3,702,608 to Tibbs, and 3,880,163 to Ritterskamp, as well as the first above-identified patent.
It is also known to provide a "tracked" injection wherein the medicament is caused to issue from the needle during movement of the needle into the patient's flesh for preventing tissue damage that would otherwise be caused by a "balloon" injection, wherein substantially all of the medicament is deposited after the needle reaches maximum penetration.
A problem with the syringe and ampule devices of the prior art is the danger of injury to the patient and others by the needle subsequent to the delivery of the medicament. (In the case of syringes, such danger is also present prior to medicament delivery.) For example, medical care providers can be accidentally scratched or punctured by the needle, being potentially harmed aside from the injury itself by residual quantities of the medicament. This danger is a particularly serious in situations wherein the needle may have become contaminated by dangerous substances, such as body fluids containing HIV virus.
Thus there is a need for a hypodermic injector device that reliably and safely facilitates administration of a medicament dosage without subjecting the patient or others to contamination or injury from the device, that is effective for delivery of the medicament in a tracked injection below a predetermined depth, and that is inexpensive to provide and easy to use.